JPS60193882A - Drain device for floating roof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION l) BACKGROUND OF THE INVENTION (11) Field of the Invention The present invention relates to a drain device for use with a floating roof in a storage tank, and more particularly to a drain device for a floating roof of an oil tank using fixed pipes and swivels. It is related to.

(2) History of the Prior Art It is well known to store volatile liquids such as stone Mh and other petroleum products in large tanks of approximately cylindrical shape and equipped with floating roofs. A floating roof, roughly circular in diameter and slightly smaller in diameter than the inside of the tank, floats on the petroleum or other liquid in the tank and moves up and down within the tank as the height of the liquid changes. Floating roofs that protect oil from external contaminants usually include one or more seals that seal a small area between the outer edge of the floating roof and the inner wall of the tank, while also allowing the roof to move up and down within the tank. Equipped with equipment. These sealing devices allow very little or no vapor to escape from inside the tank to protect the environment, and at the same time prevent rainwater,
Prevent dirt and other external elements from entering the oil stored in the tank. An example of this type of seal is U.S. Pat. Transferred to ).

Most floating roofs of this type are constructed to drain water toward a low point in its center.

This tends to direct rainwater away from the outer edges of the floating roof where it could eventually damage the seal and flow into the oil in the tank. A low point in the center of the roof has a drain that leads to a water collection basin on the underside of the roof, into which rainwater that collects on the roof is safely sent through a drain system to the outside of the tank. I can do it. The drainage system, which is essentially located inside the tank and submerged in the oil, may consist of any of a number of different basic systems. Traditionally, floating roof drain systems have been constructed by connecting several relatively inflexible pipes together by a swivel joint to create a flexible system that extends from the flood drain to the lower portion of the tank wall. It was composed by putting it together. In the lower part of the tank wall, one of a number of rigid pipes exits the tank and drains rainwater that collects in the center of the roof to a location outside the tank where it can be safely and properly disposed of. was made so that it could be disposed of. Another type of draining device that has become widely used in recent years is a length of flexible pipe or pipe connected between the collector and the tank wall and placed within the oil or other liquid in the tank. Flexible water pipes are used.

Drain equipment for use with floating roofs.

bending through a considerable range of motion to allow vertical movement of the floating roof between its highest position at the top of the tank and its lowest position where the roof is a relatively small distance above the bottom of the tank must be able to do so. It should be noted that such a drain device must be able to operate relatively leak-free even in the presence of significant pressure differences. The pressure of oil or other liquid within the tank is usually significantly greater than the pressure within the drain device itself. The natural tendency is for oil with higher pressure to leak into the drain system and escape. Because of the relatively large dimensions and consequent bulk of common drain devices, they tend to be subject to considerable forces on various parts, which stresses can damage or even destroy those parts. hand.

This may render the drain device useless. Since gravity is relied upon to drain rainwater from the floating roof through a drain system, it must be such that it provides a positive gravity at all times and even as the height of the floating roof changes.

7 in the case of a drain device in the form of an inflexible water pipe and a rotary joint
Swivel joints are designed to rotate or pivot about a predetermined axis. Usually, the two curved tubes are allowed to rotate relative to each other by sealed bearings.

Although the bearings are sealed, the seals tend to break or leak relatively easily. This is largely due to the fact that all of the stress on the swivel actually occurs in the sealed bearings where the relative motion occurs.

It is also due to the fact that such swivel joints are typically designed for use in other environments where the pressure within the joint is much greater than the pressure outside the joint. Such fittings are rarely designed to withstand significant external fluid pressures. Damage or destruction of a seal or bearing can allow oil to leak from inside the tank to the drain system. It can also result in rainwater and other contaminants leaking into the oil in the tank.

Repairing or replacing a damaged swivel is time consuming and expensive, and often requires complete draining so that a drain system can be accessed from within the tank.

It was because of such problems that flexible water conduit type drain devices were developed. Such devices typically employ a single flexible pipe or conduit extending between a collection channel located below the center of the shingle roof and the lower portion of the tank wall. The flexible water conduit bends as necessary to accommodate the vertical movement of the floating roof and at the same time provide a drainage channel for rainwater or other material that collects on the roof. The flexible water conduit 1 is usually capable of bending at any point along its length so that no part of it is subjected to significantly greater stress than any other part. This eliminates the need for sealed bearings within the joint.

However, flexible conduit drain systems are not without their own problems. On the one hand, we designed a flexible conduit that can maintain an effective seal between the interior and exterior when there are significantly large external pressure differentials and the highly volatile nature of oil, gasoline, and other petroleum products. It is relatively expensive to make. Another problem is that flexible water conduits tend to float. As a result, flexible water conduits often form loops or at least high points within them. This necessitates adding a weight or ballast to each section of the flexible conduit to counteract the positive gravity action of the drain system and reduce the tendency of the conduit to float.

The relative advantages of a non-flexible water pipe one-turn joint type drain device and a flexible water pipe type drain device are described in the Oil and Gas Journal (OIL AND GAS JOTIJFN/
Ray E. Detzker, “Careful Proposition 1 remains the key to a good floating roof drain” (Care V.), June 1, 1981 issue, pages 107-110.
fujDeaign Remains Key To
Good Floating-Roof Drains)
It is discussed in the paper. This paper considers both types of drain devices before concluding that flexible conduit systems are the most promising due to trenching problems associated with using swivel joints in non-flexible conduit single-swivel systems. Explaining.

Detzker's article points out that most of the problems with single swivel joint systems for rigid water pipes are due to the swivel joints currently in use. Although this paper acknowledges the problems inherent in single-flexure conduit devices, these problems are easier to overcome than the basic problems that characterize the swivel types currently in use. I think I can overcome this. Accordingly, this article points out that it would be desirable to provide an improved swivel joint for use with a rigid water conduit, swivel joint type drain device. Inflexible water pipe.

Swivel-type drain devices were among the first to be developed, but avoided some of the limitations inherent in flexible conduit-type and other types of devices, and avoided the problems present in swivels. If it can be minimized or eliminated, it appears to be a valid choice for many applications.

2) Summary of the Invention The present invention provides a highly improved swivel-type inflexible water conduit, a swivel-type floating roof drain system. The rotary joint according to the present invention uses a frame that rotates along one axis and has a pair of pipe joints mounted on both sides of the frame. This fitting is made to easily connect to the ends of several rigid tubes used within the drain system. The ends of a pair of inflexible tubes are joined together by a swivel joint.

-1 placed within a frame and facing each other at both ends
They are joined together by a single flexible tube or hose connected to a pair of fittings. This flexible tube bends easily to allow the frame to pivot over a relatively wide range of angles while continuously maintaining a connection between the two coupled rigid tubes. This eliminates the need for joints that require sealed bearings.

This pivoting frame is constructed to withstand most of the stress on the joint, allowing the flexible tube to bend as needed to relieve most of the force on it. Since this entire drainage system requires only a relatively small amount of flexible piping, such piping can be used even if the external pressures on it are significant and the liquid surrounding the flexible pipes is of a highly volatile nature. , can be of very high quality so as to be virtually leak-proof.

In a preferred embodiment of the drain device according to the invention, 1
Each swivel joint consists of a pair of identical side frames. Each side frame has a central portion connecting a pair of opposing leg portions.

Each of the leg sections of one side frame can be connected to and pivoted from a different section of the leg section of the other side frame such that the entire frame of two different side frames can pivot around a single central axis. It looks like this. A pair of different fittings are mounted on the outside of the central portion of each side frame and are generally ring-shaped to readily receive standard fitting flanges on the ends of a single rigid tube. Each of the ends of the single flexible tube inside the frame is connected to a different side of the two fittings by a device including a tap, a tap ring and a collar. A tap that is hollow and generally circular in shape includes a large diameter portion that is located within the associated ring-shaped fitting and that is attached, such as by welding, to the wall of a generally circular hole within the fitting. There is. The tap tapers from a larger diameter portion to a second smaller diameter portion, and the smaller diameter portion receives one end of the flexible tube on its outer side through a tube diameter reduction action. The fitting is completed by a tap ring on the outside of the tap at the tapered portion of the tap and a hollow, generally cylindrical collar placed on the outside of the end of the flexible tube opposite the smaller diameter portion of the tap. . The flexible tube consists of inner and outer wire helices with a flexible hose disposed between them.

5) Detailed Description The foregoing and other objects, features and advantages of the present invention will become apparent from the following more detailed description of preferred embodiments of the invention, which are illustrated in the accompanying drawings.

1 and 2 show a storage tank 10 having a roughly cylindrical shape. The storage tank IO has a relatively flat bottom 12 and a generally cylindrical side wall ILL.

The side wall ill consists of a series of steel plates 16 connected by welding or riveting in the manner commonly used in the construction of storage tanks for petroleum or other petroleum products.

The storage tank 10 has a floating roof 18 which is approximately circular and has an outer diameter slightly smaller than the inner diameter of the side wall 111. The roof 18 floats on the surface of a liquid 20, such as oil, stored in a tank io. A sealing device 22 extends between the outer edge of the roof 18 and the inner surface of the side wall Ill of the tank 10 to seal the space therebetween while allowing the roof 18 to move up and down within the tank 10. 1st
In the figure, a relatively large amount of liquid 20 is placed in the tank 10 so that the roof 1g is placed near the top of the tank 10.
Most of the liquid 20 is in the tank 1 at the bottom of the tank 10 at the 1λ end of the cleaning port.
It has been removed from O.

The floating roof 1g is configured to direct rainwater falling on it away from the sealing device 22 and towards the drain 2II located in the center of the roof 18. The drain 211 drains rainwater into a water collection channel 26 arranged below the central portion of the roof 18. The water collection system 26 is connected to the tank 1 by a drain device 28.
Connected to the outside of 0. Drainage system 2g includes a relatively inflexible first pipe 32 extending generally horizontally outwardly from the side of catchment canopy 26 and connected to second relatively inflexible pipe 32 by a first swivel 511. There is a tube 30.

The second rigid tube 52 is connected by a second swivel joint 58 to the fifth relatively rigid tube 3'6.

The fifth rigid tube 56 has a substantially right-angled bend IIO directly below the second swivel 58 . The third rigid tube 36 is connected to the fourth relatively rigid tube by a fifth swivel ttU. The fourth inflexible tube 42 is connected to the fourth rotary joint 1
18 to a fifth relatively inflexible tube II6. The fifth rigid tube 116 extends from the side wall of the tank IO to extend the external hedrainage device 28 of the storage tank IO.
It extends through the bottom of the l.

Rainwater that collects on the roof 18 flows into the water collection canopy 26 through the drain 2II. From the water collection channel 26, rainwater is transferred to the first inflexible pipe 0. First swivel joint 511, second rigid tube 52, second swivel joint 58. Fifth inflexible tube 56, fifth swivel joint 11t+, third inflexible tube 112° fourth swivel joint 118
and flows to the outside of the tank 10 through the fifth rigid tube 116. It will be appreciated that the drain device 28 must be flexible to provide for different vertical positions on the roof 18. At the same time, the dimensions and nature of the drain device 28 are determined by the fitting 51.
1.3g, l1ll, and l18 each bend along a single axis or pivot to remain approximately in a single plane as the drain device 28 bends to accommodate repositioning of the roof 18. It needs to be like that.

Despite this, due to the upright size and bulk of the drain device and the relative distance in which the drain device 28 is moved through the large volume of liquid 20, the stress of the kana can be applied to various parts of the drain device 2g. It takes.

For liquids with relatively high density such as oil, drain equipment 2
It will also be appreciated that significant gravity is applied to the exterior of the drain device 28 so as to create a significant H-force difference between the outside and inside of the drain device 28. It is also important that the drain system 28 avoid creating loops or upslopes therein that would interfere with the positive gravity water supply down the collection channel 26 to the fifth rigid tube 116.

This is connected at a first end to a second rigid tube 32.

It is assisted in part by a single chain 50 connected at the opposite second end to a fifth rigid tube 6.

It will be observed in FIG. 1 that when the floating roof 18 is in its highest position 7 the drain arrangement 28 provides a positive gravity flow from the collection well 26 to the fifth rigid tube 46. The second and fifth rigid tubes 52 and 36 are relatively steeply inclined. Although the fourth inflexible tube 112 has somewhat less inclination,
It is tilted by a sufficient amount to facilitate gravity flow of rainwater into the fifth rigid pipe 116 and out of the tank 10. The chain 50 has a fourth rigid tube 142 and a fifth rigid tube 116.
the second rigid pipe 5 so as to maintain a convenient drainage angle with respect to the
Lift against 2.

When the floating roof 18 is lowered from the highest position shown in FIG. 1, the second rigid tube 52 pivots upwardly relative to the first rigid tube 50 via the swivel joint 511.

At the same time, the fifth rigid tube 56 is connected to the second tube at the swivel 58.
The angle formed by the inflexible tube 32 gradually becomes smaller. At the same time, the fifth rigid tube 56 and the fourth rigid tube L2 move toward the horizontal position. Once the floating roof 18 has moved all the way to the lowest position shown in FIG. 2, the second rigid tube 32 assumes a slightly tilted position from the horizontal. At the same time, the fifth and fourth rigid tubes 56 and 42 assume a substantially horizontal position with the fifth rigid tube 116. Various inflexible tubes 50, 52, 36, 11
2 and 116 are either horizontal or downwardly sloped so that there is a positive gravity between the water collection canopy 26 and the fifth rigid tube 116 so that rainwater that collects on the roof 18 can easily drain to the outside of the tank 10. The feed is maintained forever.

FIG. 5 shows the drain device 28 of FIGS. 1 and 2 in greater detail. The roof 18 of the drain system e28 is the second one.
The position taken when it is at the lowest position in the figure is shown by a solid line. The drain device 28 is shown in dotted outline in the position it assumes when the roof 1g is in its highest position shown in FIG. A fifth rigid tube L16 has a support phase 52 attached to the bottom 12 of the tank IO near the opposite end of the side wall ill of the tank IO.
is supported by When the roof 18 reaches the lowest position shown in FIG. 2 and the fourth inflexible tube 112 is lowered to a substantially horizontal position, the support member 55 attached to the bottom 12 moves the fourth inflexible tube 112. To support. A support member 56, also attached to the bottom 12, supports the fifth rigid tube 56 when the roof 18 is in its lowest position.

It is clear from Figures 1 and 2 and from Figure 5 that the various swivel joints must be able to carry out a considerable range of angular movement while at the same time sustaining considerable pressure differences and considerable forces. It will be recognized. In the particular configuration of FIGS. 1 to 2, the second swivel joint 5g forms an angle of approximately 90° when the roof 18 moves between the highest position in FIG. 1 and the lowest position in FIG. Move until. The considerable weight and bulk of the various tubes and the considerable dimensions of the drain device 28 place significant stresses on the various swivels as the drain device 28 is lowered and raised. As previously mentioned, the single-swivel joint must flex in a manner that keeps the drain device 28 in substantially the same plane as the drain device 28 bends in response to movement of the roof 18. Swivel joint arrived.

The configuration of 3g, 44 and 48 allows them to pivot only about a single pivot axis as described below. It should be noted that the design of such fittings is such that they can withstand the significant pressure differentials and significant stresses normally found in this type of environment.

4-8 illustrate various swivel joints 51j, 38.1414 and II8 in the configuration of FIGS. 1-5.
2 shows a preferred embodiment of a swivel 18 that can be used as a swivel. The rotary joint 58 is a relatively inflexible tube 60
and is shown connected to a relatively inflexible tube 62. The swivel joint 58 is the swivel joint l1 of FIGS. 1 to 5.
11, the rigid tubes 60 and 62 would each consist of the second rigid tube +42 and the third rigid tube 36.

The rigid tube 6o terminates in a generally disc-shaped flange 64 connected to the swivel 58 by a fitting 66. The rigid tube 62 terminates in a disc-shaped flange 68 that is connected to a fitting 70.

Fittings 66 and 70 are attached to opposite portions of pivotable frame 72 within single swivel fitting 58.

Pivotable frame 72 has opposing side frames 74 and 76 of virtually identical construction. The side frame 711 has a pair of leg portions 80 and 82 that extend from one side to the other and have a central portion 7 to which a 9° pipe joint 66 is attached.
There are 8. The leg portions 80 and 82 are spaced parallel to each other and are generally perpendicular to the central portion 78. Side frame 76 includes a central portion 84 extending between opposing leg portions 86 and 88 to mount fitting 72 . The leg portion 86 has a bolt 90 extending through both leg portions and secured to the outside thereof with a nut 92.
It is connected by a swivel and can be rotated. The leg portion 88 is pivotably connected to one leg portion 82 by a bolt 9 extending through both leg portions and having a nut 96 mounted on the outside thereof. Pol) 90
and 91I for the pivotable frame 72. Thus, along the same axis that defines the pivot axis for the swivel 58.

A flexible tube 98 within the pivotable frame 72 includes:
An o'ft flexible tube 98 whose first end 100 is connected to fitting 66 and whose second end 102 is connected to fitting 70 has a pivotable frame 72 connected to bolts 90 and 911.
The tubes 60 and 62 can be bent to maintain the connection between the tubes 60 and 62 when pivoted around the tubes.

As can be seen in FIG. 8 as well as in some of the other figures, each of the central portions 78 and 811 of the side frames 711 and 76 consists of two different pieces of metal with a small gap 1 oll between them. Central portions 78 and 811
Also includes a first end 100 and a second end 1 of the flexible tube 98.
There are circular holes 106 and 108 that receive 02, respectively.

Fittings 66 and 70 are attached to the outer surfaces of central portions 78 and 811, respectively, by welding or other suitable means. The disc-shaped flange 61I attached to the end of the rigid tube 60 is a flange 611. a plurality of holes extending through respective holes in fitting 66 and central section 78)'
110 for easy attachment to pipe fitting 66. Each of the plurality of nuts l-112 is fixed to a different bolt 110 adjacent to the central portion 7g. Similarly, tube 6
The flange 68 housed at the end of the flange 68,
A plurality of bolts 1 extend through respective bored holes in the pipe fitting 70 and central portion 8111C and receive a plurality of nuts 66.
It is fixed to the pipe joint 70 by 11↓.

Each of the opposite ends 100 and 102 of the flexible tube 98 is fitted into a respective fitting 66 and 70 by a reduced tube diameter configuration shown in detail in FIG. As seen in FIG. 7, a hollow circular tap 118 extends from the central portion 814 and fitting 70 into the interior of the side frame 76. The fitting 70 is generally ring-shaped with a circular hole 120 therein.

Tap 118 has a first generally cylindrical portion 122 of increased diameter that extends through circular hole 108 in central portion 84 and fits within circular hole 120 in fitting 70 . A first portion 122 of tap 118 is secured within circular hole 120, such as by welding, with weld bead 1211 shown in FIG.

As the tap 118 extends from the fitting 70 into the interior of the side frame 76, it tapers through a tapered portion 126 to a second generally cylindrical portion 12g=i of reduced diameter smaller than the diameter of the first portion 122. It has become. The flexible tube 98 is, in this example, a single flexible hose 15 made of alternating layers of tripropylene fabric and film to make it impermeable to highly volatile liquids such as kalin.
It consists of 0. Hose 150 is held in a generally cylindrical shape while being kept very flexible by outer wire helix 132 and inner wire helix 14. Inner wire helix 1511 is disposed inside outer wire helix 132 with flexible hose 130 disposed therebetween. The various coils of the wire helix 152 and H1'5+4 are arranged in a staggered manner. The inner diameter of outer wire helix 1 to 2 is inner diameter 1111 wire helix 151
Slightly smaller than the outer diameter of 1. As a result, the flexible hose 150 is connected to the inner wire helix 1 to 4 as shown in No. 7N.
It undulates above and below the outer wire helix 132.

The flexible tube 98 extends outside the second portion 128 of the tap 11g, which is surrounded by a hollow, generally cylindrical collar 6. A splice 156 of approximately the same length as the second portion 128 of the tap 118 is bent inward at one end thereof to form a ring lug 8 extending over the outer surface of the second portion 12g of the tap 118. It is supposed to be done. Lip 138 tapers 11 at tapered portion 126
8 and is in contact with a tap ring 1110 having a substantially rectangular cross section. A snug, virtually leak-free fit is provided by swaging the end of the flexible tube 98 with the collar 156 and tap ring 1110 over the outside of the second portion of the tap 118. Although not shown in FIG. 7, the second portion 1 of the tap 11g
The outer surface of the 2g has a very fine helical thread. The end of the flexible tube 98 is rotated relative to the tap 18 in the direction of the thread during the aging operation.

The first end 100 of the flexible tube 98 is configured with a second end 10
2 and is connected to the pipe joint 66 in the same way. It will be appreciated that the swivel joint 58 shown in FIGS. 4-8 can be easily bent while at the same time providing a strong and relatively leak-free joint. Side frame 71, preferably of stainless steel construction
1 and 76 in combination with steel pipe fittings 66 and 70 provide a relatively strong and sturdy framework capable of withstanding the significant stresses placed on drain system 28. It has been found that if the stresses are large enough, the two tubes 60 and 62 will buckle before the swivel 58 itself undergoes significant deformation or failure. The flexible tube 98, which can be easily bent in response to the rocking motion of the pivotable frame 72, is virtually completely impermeable to highly volatile liquids even with pressure differences of 9 to 1. wire helix 152 and 1511
is reinforced by. Tap 1 in which both ends of the flexible tube 98 use a joint ring 156 and a tap ring 11jO
18 is swaged by fittings 66 and 70 on both ends.
gives a relatively tight leak-free fitting.

[Brief explanation of the drawing]

FIG. 1 is a side view of a storage tank with a floating roof, with the tank partially cut away to show the drain system according to the invention. The second garden is similar to FIG. 1 but with the floating roof in the lowered position; FIG. 5 is a side view of the drain device of FIGS. 1 and 2 showing the drain device in great detail; 4 is a perspective view of the swivel joint used in the drain device of FIG. 1, FIG. 5 is a different perspective view of the swivel joint of FIG. 4, and FIG. 6 is a g111 plane view of the swivel joint of FIG. 4. Fig. 7 shows the fourth
FIG. 8 is a plan view of the swivel joint of FIG. 4, and FIG. 8 is an end view of the swivel joint of FIG. 10--tank, 111--tank side wall, 18-1 floating roof. 24--Drain, 26--Water collection, 28--Drain device, 30.32, 36, 112, 116, 6Q, 62-
A rigid tube. 311.3g, 1111,118; 5g-single joint,
50--strand. 66.70--one fitting, 72--frame, 98--one flexible tube, 100--first end i of flexible tube 102--
Second end of the flexible tube. Engraving of drawings (no change in content) FIG, I FIG, 2 Procedural Amendment-1 June 6, 1982)] Director of the Patent Office Kazuo Wakasugi L Case Indication 1982 Patent Application No. 1157II8 Relationship Patent Applicant 8, (Name) Pivot Masters Inc. 4, Agent

Claims (1)

[Claims] 1. A substantially cylindrical tank having a side wall. a substantially circular floating roof disposed within the tank and having a water collection hole on the lower side of the central portion; a flexible tube arrangement disposed within the tank and connecting the collection well to a portion of the side wall of the tank near the bottom of the tank; The flexible tube apparatus includes a swivel joint that joins two relatively inflexible tubes together. The said swivel joint is. a hinged frame having a pair of opposing ends; a pair of pipe fittings respectively attached to different ends of the pair of opposite ends of the hinged frame; a first pipe disposed inside the hinged frame and connected to a first joint of the pair of pipe joints;
and a second joint connected to the second end of the pair of pipe joints.
1. A drain device for a floating roof, characterized in that it is formed by combining a single flexible pipe having an end with a flexible pipe. 2. a hinged frame having a pair of opposite ends; a pair of pipe fittings respectively attached to different ends of the pair of opposite ends of the hinged frame; a flexible tube having a first end connected to a first fitting of a pair of pipe fittings and a second end connected to a second fitting of the pair of pipe fittings; A floating roof drain device with multiple circulation joints.